Organopolysiloxane composition for use in release paper or release film

Abstract

In the present invention, compounding an addition-reaction-curable organopolysiloxane composition with a specific amount of an organopolysiloxane compound that has three or more (meth)acryl groups in the molecule and a weight-average molecular weight of 1,000 or greater yields an organopolysiloxane composition for use in a release paper or release film in which addition reactions can occur using a small amount of platinum family metal catalyst, cured films can be formed having a peeling strength approximating levels encountered in the past, and addition-reaction-prompted curing will proceed even on a base material containing a catalyst-poisoning component.

The invention claimed is: 
     
       1. An organopolysiloxane composition for release paper or release film consisting of the following components (A) to (D):
 (A) an organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule, but not at least three (meth)acrylic groups, 
 (B) an organohydrogenpolysiloxane having on the average at least two silicon-bonded hydrogen atoms (i.e., Si—H groups) per molecule, but not at least three (meth)acrylic groups, in such an amount that the moles of Si—H groups in component (B) is 1 to 5 times the moles of alkenyl groups in component (A), 
 (C) an organopolysiloxane compound having at least three (meth)acrylic groups per molecule and represented by the general formula (3)
     M   i   a   M   1A   b   D   1   c   D   1A   d   T   1   e   T   1A   f   Q   1   g   (3)
 
 
 wherein M 1  is R 1   3 SiO 1/2 , M 1A  is R 1   2 ASIO 1/2 , D 1  is R 2 SiO 2/2 , D 1A  is R 1 ASIO 2/2 , T 1  is R 1 SiO 3/2 , T 1A  is ASiO 3/2 , and Q 1  is SiO 4/2 , 
 R 1  is each independently a C 1 -C 18  unsubstituted or substituted monovalent hydrocarbon group, or alkoxy group, hydroxy group, epoxy group, or polyoxyalkylene group, 
 wherein in the groups R 1   2 ASiO 1/2 , R 1 ASIO 2/2 , and ASiO 3/2 , A is CH 2 ═CR 2 COR 3 —, 
 R 2  is hydrogen or methyl, 
 R 3  is OR 4  or R 4 , 
 R 4  is a C 1 -C 20  divalent group which may have a branched or cyclic structure and may contain an epoxy group, ester bond, urethane bond, ether bond, isocyanate bond, or hydroxy group, 
 the subscript a is an integer of 0 to 10, 
 the subscript b is an integer of 0 to 5, wherein b is an integer of 2 to 5 when a is 0, and b is an integer of 1 to 5 when a is 1, 
 the subscript c is an integer of 5 to 300, 
 the subscript d is an integer of 3 to 200, 
 the subscripts e and f each are an integer of 0 to 10, and 
 the subscript g is 0 or 1; and 
 wherein the organopolysiloxane compound has a weight average molecular weight of at least 1,000, in an amount of 0.01 to 5 parts by weight per 100 parts by weight of component (A), and 
 (D) a platinum group metal base catalyst in an amount to give a platinum concentration of 1 to 100 ppm by weight based on the total weight of components (A), (B), (C), and (D), and optionally further consisting of one or more of: 
 (E) a reaction inhibitor, 
 organic solvent, 
 aryl group-containing silicone resins other than components (A) to (C), and silica. 
 
     
     
       2. The organopolysiloxane composition of  claim 1 , which contains (E) 0.01 to 5 parts by weight of said reaction inhibitor per 100 parts by weight of component (A). 
     
     
       3. The organopolysiloxane composition of  claim 1 , wherein component (C) is an organopolysiloxane compound having at least three (meth)acrylic groups on side chains. 
     
     
       4. The organopolysiloxane composition of  claim 1 , wherein component (C) is an organopolysiloxane compound having at least five (meth)acrylic groups per molecule. 
     
     
       5. The organopolysiloxane composition of  claim 1 , wherein the platinum group metal base catalyst (D) is contained in an amount to give a platinum concentration of 1 to 60 ppm by weight based on a total weight of components (A), (B), (C), and (D). 
     
     
       6. The organopolysiloxane composition of  claim 1 , wherein the platinum group metal base catalyst (D) is contained in an amount to give a platinum concentration of 1 to 40 ppm by weight based on a total weight of components (A), (B), (C), and (D). 
     
     
       7. The organopolysiloxane composition of  claim 1 , wherein the platinum group metal base catalyst (D) is contained in an amount to give a platinum concentration of 1 to 30 ppm by weight based on a total weight of components (A), (B), (C), and (D).